Commercial plastics and elastomers are polymeric materials which have been employed in a wide variety of uses. These can be generally classified as being thermoplastic, elastomeric or thermoset. There are literally dozens and perhaps even hundreds of polymers which have present commercial value or potential commercial value.
Many if not most of these polymers have defects or disadvantages which detract from the desired full spectrum of properties to be possessed by a polymer for a given purpose.
Therefore, it has become conventional and even a very highly sophisticated practice to incorporate various additive materials in these polymers in order to improve the polymer in a particular property or to neutralize or blunt the effect of a serious defect in a polymer characteristic.
There are wide varieties of such additives. They include such things as anti-oxidants, anti-stats, colorants, flame-retardants, heat stabilizers, lubricants, plasticizers, preservatives, processing aids, UV absorbers, and the like.
Additives in order to be effective must be capable of being mixed thoroughly with the particular plastic to be improved, i.e., the additive must be compatible with the polymer. Desirably, the additive should be non-extractable from the polymer matrix. That is, the environment in which the plastic is used should not adversely remove the additive from the polymer. For instance, a polymer which is going to be used in a dishwashing machine should not have additives which are extracted easily with the action of hot soapy water.
Also, additives should have the property of being non-volatile. Thus, at the temperatures of processing, i.e. extrusion and molding, the additives must not be volatilized out of the polymer matrix at these temperatures. Furthermore, the additives must be relatively heat stable so that at these temperatures they do not tend to degrade. Thus, for many additives the quality of being non-migratory is highly desirable.
Most of the additives conventionally used by the prior art are deficient in these characteristics.
Even when grafted polymers have been modified, the process has not been solvent phase and the object has not been the preparation of additives.
Japanese application Nos. JA 16396/68, 16395/68, 16393/68, 16392/68, 7348/69, 7347/69, 7346/69, 7345/69, 2719/69, 2718/69, 2717/69, 2716/69, 2715/69, 2714/69, 21493/69, 21492/69 represent art of some interest.